Indigo-white compound and process of making same.



UNITED STATES PATENT OFFICE.

MAX BAZLEN, OF LUDWIGSHAFEN, GERMANY, ASSIGNOR To THE BADISOHE ANILIN AND SODA FABRIK, OF SAME PLACE.

INDIGO-WHITE COMPOUND AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent N 0. 657,307, dated September 4, 1900.

Application filed MayZZ, 1900. Serial No. 17,546. (No specimens.) I

To all whom it may concern.-

Be it known that I, MAX BAZLEN, doctor of philosophy, a subject of the King of Wiirtemberg, residing at Ludwigshafen-on-the-Rhine, in the Kingdom of Bavaria and Empire of Germany,have invented new and useful Improvements in Stable Indigo-White Compounds of which the following is a specification.

My invention relates to the production of a new compound of indigo-white,which is stable in the presence of air, but whichiby the action of caustic alkalies is readily reconverted into indigo-white or indigo. I

My new body can be obtained by acting on indigo-white suspended or dissolved in water,

acetone, alcohol, or other suitable medium tion product separates out as a difficultlysoluble body and is filtered ofi. To obtain the remainder neutralize the filtrate with solid sodium carbonate and distil ofi the acetone.

Instead of acetone water or alcohol may be employed in the above example. When using alcohol, however, the product obtained is not quite so pure.

My new product is a powder, which is, as a. rule, more or less dark colored and is stable in the presence of air. It is difficultly soluble or insoluble in most of the ordinary solvents and cold dilute caustic soda, but is somewhat soluble in boiling acetone. On warming with caustic-soda lye it is reconverted into indigowhite. By heating with concentrated sulfuric acid and pouring into water a blue solution is obtained.

Now what I claim is 1. The process of producing a stable indigowhite body, by treating indigo-white with phosgene.

2. The process of producing an indigowhite body by treating indigo-white with phosgene in the presence of caustic soda.

3. As a new product, the body which can be obtained by treating indigo-white with phosgene which is stable in the presence of MAX BAZLEN.

Witnesses:

PERCY J. JONES, J. L. HEINKE. 

